Sub-Lithographic Patterning of Ultra-Dense Graphene Nanoribbon Arrays

by Ke Li

Institution: The Ohio State University
Department: Physics
Degree: MS
Year: 2009
Keywords: Physics; GNRs; graphene nanoribbons; nanofabrication; SNAP
Record ID: 1843561
Full text PDF: http://rave.ohiolink.edu/etdc/view?acc_num=osu1250545004


Graphene has become a rising star in the field of physics and material science since its discovery in 2004. Considerable amount of potential applications, particularly graphene-based electronics, has been proposed due to graphene’s excellent switching speed and high carrier mobilities (potentially even ballistic transport). The reality is, however, that spatial confinement, such as narrow edge (=10 nm) ribbons or quantum dots, must be imposed on graphene sheet in order to open up energy bandgaps adequate for room-temperature transistor operation, and there seems to be no high-throughput tool to fabricate such structures on graphene at this time, since sub-10 nm scale is barely at the resolution limit of standard electron beam lithography. This thesis describes a new approach to fabricate graphene nanoribbons (GNRs), based on the recent development of sub-lithographic patterning using the superlattice nanowire pattern transfer (SNAP). This top-down technique will be described in detail, and how to change its material base from Si to graphene will be discussed. In principle ultra-dense (15 nm in pitch) GNR arrays can fabricated with relative high throughput (up to 400 GNRs each time), with reliable control over the GNR width (from hundreds of nm down to 7 nm). However, anisotropic dry etching must be developed in the further before GNRs can be realized using this technique. The SNAP technique, together with the recent progress in wafer-size growth of graphene, potentially allows the mass-production of graphene-based circuit.